UCH (BCM) how to remove and check

[Mat Jones]

I seen a few faults on this forum that I think are to do with the uch so I thought this would help.
The uch is a computer linked into your cars ecu, this controls things like wipers, lights, locks etc. There are a few common things that could point to the uch being faulty like lights behaving strangely, not starting, wiper going mad, windows acting strange. Some times its possible to physical damage to your uch and it is not hard to remove and check.
This is a guide that will help some.
1. go to the n/s/f and remove the fuse cover
2. Then remove the 20 torx screw as pointed

3. Prize the bonnet pull off like in the photo

4. Pull back the trim and remove the 13mm bolt holding the l shape bracket

5. Now undo the three plugs off the uch look carefully how to, 2 of them need to be pushed over

6.Now the uch will pull down towards you, once you have this on the bench push lugs all round and remove as shown

7. Inspect the circuit board for water/any damage as shown

8. Play close attention to the chip pointed out if you have immobiliser/start problems as this is the one that hold the security info

Hope this helped, give us a like if so. A not in step 5 you can see the words uch n2. The N2 part is the level of spec the uch is capable of there are 3 in total N1, N2 and N3

 

[fairm010]

Appreciate it mate, this will help sort the relay in my UCH for my dodgy electric window!

 

[ADS_V6]

your a legend mat,if your ever around cardiff ill pay you to look at mine

 

[Joshjoshjosh]

Sorry to bring up an old thread, but does anyone know which part of the pcb controls the front wipers?
Every time i switch on the ignition in my clio the front wiper fuse blows. Had it in the garage for 2 weeks and they wittled it down to a faulty uch but tried to fit and reprogram a second hand one which was never going to work. Wondering if i can do a repair to the pcb myself instead of paying someone £100 to do it for me.

 

[barnesautos]

Sorry to bring up an old thread, but does anyone know which part of the pcb controls the front wipers?
Every time i switch on the ignition in my clio the front wiper fuse blows. Had it in the garage for 2 weeks and they wittled it down to a faulty uch but tried to fit and reprogram a second hand one which was never going to work. Wondering if i can do a repair to the pcb myself instead of paying someone £100 to do it for me.

Why don't you just power up the wiper motor from 12v not from the UCH .

What pin in the motor looses its fuse power. ?
Have you disconnected the wiper motor connector and then does it still blow the fuse ?

 

[Joshjoshjosh]

I've only just got back from picking it up at the garage, i haven't had a chance to do much digging of my own just yet but prior to going into the garage i did disconnect the motor and the fuse would still blow.

Will have to have a good look at it today and see what i find.

 

[mat@86]

I seen a few faults on this forum that I think are to do with the uch so I thought this would help.
The uch is a computer linked into your cars ecu, this controls things like wipers, lights, locks etc. There are a few common things that could point to the uch being faulty like lights behaving strangely, not starting, wiper going mad, windows acting strange. Some times its possible to physical damage to your uch and it is not hard to remove and check.
This is a guide that will help some.
1. go to the n/s/f and remove the fuse cover
2. Then remove the 20 torx screw as pointed
View attachment 133873

3. Prize the bonnet pull off like in the photo
View attachment 133874

4. Pull back the trim and remove the 13mm bolt holding the l shape bracket
View attachment 133875

5. Now undo the three plugs off the uch look carefully how to, 2 of them need to be pushed over
View attachment 133876

6.Now the uch will pull down towards you, once you have this on the bench push lugs all round and remove as shown
View attachment 133877

7. Inspect the circuit board for water/any damage as shown
View attachment 133878

8. Play close attention to the chip pointed out if you have immobiliser/start problems as this is the one that hold the security info
View attachment 133879

Hope this helped, give us a like if so. A not in step 5 you can see the words uch n2. The N2 part is the level of spec the uch is capable of there are 3 in total N1, N2 and N3

Hi. Thanks for the pics it really helped. Just a question. I have the N1 uch which I removed. It does not seem to have any damage to it. My immobilizer light stays off. It does not come on at all. I got a new key, not coded yet. Got a new battery as well. But once I connected the battery. Still no immobilizer light. I've clean all the fuses and relays as well. If there is nothing wrong with the uch, what could my next step be? As I'm losing hope. Please could you give me some sort of guide line where to begin. Thanks

 

[Usr117063]

Hi. Thanks for the pics it really helped. Just a question. I have the N1 uch which I removed. It does not seem to have any damage to it. My immobilizer light stays off. It does not come on at all. I got a new key, not coded yet. Got a new battery as well. But once I connected the battery. Still no immobilizer light. I've clean all the fuses and relays as well. If there is nothing wrong with the uch, what could my next step be? As I'm losing hope. Please could you give me some sort of guide line where to begin. Thanks

He was last online in 2017. Best to put a thread in the faults section

 

[mat@86]

He was last online in 2017. Best to put a thread in the faults section

Thanks